U.S. and Canadian ships and planes continued their search for a submersible that took wealthy tourists to visit the site of the Titanic wreckage off the coast of Canada as the vessel remained missing for a third day on Tuesday.
One pilot and four passengers were on board the submersible that went missing on Sunday, the U.S. Coast Guard said, adding the vessel could stay underwater for up to 96 hours, although it was unclear if it had resurfaced but was unable to communicate.
Those aboard the submersible called Titan, the highlight of a tourist expedition that costs $250,000 per person, included British billionaire Hamish Harding and Pakistani businessman Shahzada Dawood with his son. French media also reported that 77-year-old French explorer Paul-Henri Nargeolet was on board.
"We are very grateful for the concern being shown by our colleagues and friends and would like to request everyone to pray for their safety," Dawood's family said Tuesday.
U.S. and Canadian ships and planes began swarming the area on Monday about 1,450 kilometers (900 miles) east of Cape Cod, some dropping sonar buoys that can monitor to a depth of 13,000 feet (3,962 meters), U.S. Coast Guard Rear Adm. John Mauger said.
"We are deploying all available assets to make sure that we can locate the craft and rescue the people on board," he told reporters on Monday. "It is a remote area and it is a challenge to conduct a search in that remote area."
He said officials had asked commercial vessels to help.
The wreckage of the Titanic that sank in 1912 after hitting an iceberg lies at about 3,810 meters (12,500 feet). The Titan submersible usually takes two hours to descend to the wreck.
OceanGate Expeditions, the private company that operates the submersible, said it was "mobilizing all options" to rescue those aboard the Titan.
The U.S. Coast Guard said on Twitter that a boat on the surface – the Polar Prince – lost contact with the submersible about 1 hour and 45 minutes after it began diving toward the site of the Titanic's wreckage Sunday.
Harding's stepson wrote on Facebook that Harding had "gone missing on submarine" and asked for "thoughts and prayers," but later removed the post citing respect for the family's privacy.
Harding, a UAE-based businessman and adventurer who is chairman of Action Aviation, had posted on Facebook that he would be aboard the submersible.
The expedition headed out to sea Friday, and the first dive was set for Sunday morning, according to Harding's post.
Fellow tourist, Dawood, is the vice chairman of Engro Corporation, one of Pakistan's largest conglomerates with investments ranging from fertilizers and energy to vehicle manufacturing.
SETI, the California-based research institute of which he is a trustee, said on its website that Dawood lives in Britain with his wife and two children.
The expeditions start in St. John's, Newfoundland, before heading out approximately 640 kilometers into the Atlantic to the wreckage site, according to OceanGate's website.
The British passenger ship sank on its maiden voyage, killing more than 1,500 people, a tragedy that has been immortalized in books and films, including the 1997 blockbuster movie "Titanic."
